This application claims the priority of German application No. 198 07 742.4, filed Feb. 24, 1998, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to an arrangement for sterilizing the inner surfaces of a container comprising a filling opening and a wall having at least one electroconductive layer, also comprising a reactor, which takes up the container. The reactor generates a low pressure plasma. A vacuum pump is connected to the reactor, and a conduit leads into the reactor for supplying the gas to be ionized. A first electrode can be inserted in through the filling opening into the container, and a second electrode is located outside of the container, with a high frequency generator connected to one of the electrodes.
FIG. 3 in U.S. Pat. No. 3,701,628 shows how to sterilize a container located in a reactor by way of a low-pressure plasma. The electroconductive metal walls of the reactor serve as a grounded electrode. The other electrode, connected to the high frequency generator, can be inserted through the container opening into the inside of the container. The dielectric sleeve of the container, for example of a milk carton, can comprise a layered material, of which one layer is electroconductive. The container itself stands on an insulated platform.
The sterilizing effect of the plasma to be ignited is based on a mechanical destruction of the microorganisms by ion bombardment as well as on a chemical destruction. In order to accelerate the ions to a high bombardment level, the highest possible potential difference between the plasma and the container is necessary. As, in the known arrangement, the container is located insulated between the electrodes, the wall to be sterilized is charged to the more negative, in relation to the plasma, so-called floating potential. The arising potential difference of several volts is very low and of barely any influence, the degree of effectiveness thus not being very good.